2017 Chevrolet Volt LT Hardware Modifications to allow Openpilot Operation
This is a work in progress! :)
Several people have successfully enabled Openpilot operation on 2017 LT Volts without stock Premier features. This section will cover the hardware modifications required to enable Openpilot. Remember, firmware modifications are still required.
- Radar: 13395934
- Connector: GM 19299773, or CET1259-2 (connectorexperts.com)
- Radar Connector Pins x8: 19300649
- OBDII Pins (2): J1962 Connector/Pins (amazon.com)
- Radar Grille: 84036277
In order for OpenPilot to work, at this time you must have a radar. Since the LT does not have Adaptive Cruise Control, it does not have a radar, which means you have to install one. The stock mounting location for the radar is on the LT Volt, but the LT grille is not radar compatible and the wiring harness is not installed. If you do not have a replacement grille, the old silver grille can be removed, leaving only a black base plate with a cutout for the radar. I ran my setup like this for several months without issue before I found a Premier Grille.
To install the radar the front bumper needs to be moved out of the way (only removing wheel-well and top bolts and tilting the bumper down). The LT grille also needs to be removed as it is not radar transparent. This is done by releasing a series of tabs that attach the silver grille to the black base plate.
At this point we need to build a wire harness for the radar module since the LT Volt does not have this installed from the factory. I used 4 18 gauge wires because that’s what I had laying around, you could probably get away with using a smaller wire. I bundled the 4 wires together using electrical tape wrapped around the entire length of the harness (about 15 feet), you could use something else if desired. I used a tap-a-circuit at the drivers side fuse panel to power the radar. The wiring diagram has the pins used highlighted. Here they are listed for your reference:
- Pin 6 - 12V ignition power for radar
- Pin 7 - Ground
- Pins 3, 5, 11 - Tied together, connect to OBDII Pin 3
- Pins 2, 4, 10 - Tied together, connect to OBDII Pin 11
I chose to solder and heat shrink the wires from the connector to the harness I made, for something as sensitive as this and as exposed to weather that it is, I wanted very good connections. Route the harness you made towards the drivers side following the factory harnesses, once up near the driver’s side corner of the engine compartment, find the hood release cable. In the driver’s side footwell you will see where it enters the engine compartment. I will say getting the wire into the cabin took a while for me, I ended up using a wire fish cable poked from inside the cabin to the engine compartment. It goes up and gets trapped in the vents under the windshield wipers. Then I attached the harness and pulled it into the cabin. This was by far the hardest part of this project.
Once the wires are inside the cabin we will complete the electrical connections. The power wire will go up to the fuse box in the dashboard. The ground wire will connect behind the hood release cable (that panel must be removed). The two CANBUS wires will connect to the OBDII port, the stock OBDII port will not have wires in these locations (officially these pins are considered the object detection bus on a Premier Volt).
- Clock Spring: 39136243
- Steering Wheel: 23365557
- Clock Spring Connector Pins (3): 13575867
- BCM Connector Pins: 13582297
The LT Volt does not have LKAS (Lane Keeping Assist System) or ACC (Adaptive Cruise Control) switches. The premier wheel does, and it also has a steering wheel heater! So how do we get this functionality on the LT? It’s a rather simple procedure. The wheel can be found for about $70 on ebay. You will also need a new clock spring that has the contacts required for these options. That, in addition to a few wire terminals and you have the full functionality of a Premier steering wheel. This modification is optional, as it has no real functionality on the stock fork of Openpilot. Certain forks, such as Twilsonco's, allow use of the LKAS and ACC switches to turn on and off Lateral control and change following distance.
First, disconnect the 12V battery since you will be working with the airbag.
[Airbag Coil Re-Centering](https://github.com/commaai/openpilot/files/10099263/Airbag_Steering_Wheel_Module_Coil_Centering.pdf) - If yellow locking pin was accidentally removed prior to install, or there is any doubt whether the new clock spring is centered.
One wire is required to be added between the clock spring connector (Module X85, Connector X1, Pin 15) and the BCM (Module K9, Connector X3, Pin 8). The BCM is located under the shifter center console, on the floor. The connectors are towards the drivers side.
NOTE: The LKAS LED will never light up, but it will turn LKAS off and on if you have a compatible fork of openpilot.
Two wires are required to be added at the clock spring connector (Module X85, Connector X1, Pins 8/21) for ignition power and ground. For ground I found a bare bolt behind the steering column, for power I tapped into the same ignition power tap-a-fuse of the radar.
